package com.framework.core.utils;

import java.awt.*;
import java.awt.image.BufferedImage;
import java.util.Random;

/**
 * 验证码工具类
 */
public class VerifyCodeUtil {

    /**
     * 验证码类型为仅数 0~9
     */
    public static final int TYPE_NUM_ONLY = 0;

    /**
     * 验证码类型为仅字,即大小写字母混合
     */
    public static final int TYPE_LETTER_ONLY = 1;

    /**
     * 验证码类型为数字和大小写字母混合
     */
    public static final int TYPE_ALL_MIXED = 2;

    /**
     * 验证码类型为数字和大写字母混
     */
    public static final int TYPE_NUM_UPPER = 3;

    /**
     * 验证码类型为数字和小写字母混
     */
    public static final int TYPE_NUM_LOWER = 4;

    /**
     * 验证码类型为仅大写字
     */
    public static final int TYPE_UPPER_ONLY = 5;

    /**
     * 验证码类型为仅小写字
     */
    public static final int TYPE_LOWER_ONLY = 6;

    private VerifyCodeUtil() {
    }

    /**
     * 生成随机颜色
     */
    private static Color generateRandomColor() {
        Random random = new Random();
        return new Color(random.nextInt(255), random.nextInt(255), random.nextInt(255));
    }


    /**
     * 生成图片验证
     *
     * @param type           验证码类,参见本类的静态属
     * @param length         验证码字符长,要求大于0的整
     * @param excludeString  �?排除的特殊字
     * @param width          图片宽度(注意此宽度若过小,容易造成验证码文本显示不 4个字符的文本可使)
     * @param height         图片高度
     * @param interLine      图片中干扰线的条
     * @param randomLocation 每个字符的高低位置是否随
     * @param backColor      图片颜色,若为null则表示采用随机颜
     * @param foreColor      字体颜色,若为null则表示采用随机颜
     * @param lineColor      干扰线颜,若为null则表示采用随机颜
     * @return 图片缓存对象
     */
    public static BufferedImage generateImageCode(int type,
                                                  int length,
                                                  String excludeString,
                                                  int width,
                                                  int height,
                                                  int interLine,
                                                  boolean randomLocation,
                                                  Color backColor,
                                                  Color foreColor,
                                                  Color lineColor) {
        String textCode = generateTextCode(type, length, excludeString);
        return generateImageCode(textCode, width, height, interLine, randomLocation, backColor, foreColor, lineColor);
    }


    /**
     * 生成验证码字符串
     *
     * @param type          验证码类,参见本类的静态属
     * @param length        验证码长,要求大于0的整
     * @param excludeString �?排除的特殊字符（无需排除则为null�?
     * @return 验证码字符串
     */
    public static String generateTextCode(int type,
                                          int length,
                                          String excludeString) {
        if (length <= 0) {
            return "";
        }
        StringBuffer verifyCode = new StringBuffer();
        int i = 0;
        Random random = new Random();
        switch (type) {
            case TYPE_NUM_ONLY:
                while (i < length) {
                    int t = random.nextInt(10);
                    //排除特殊字符  
                    if (null == excludeString || excludeString.indexOf(t + "") < 0) {
                        verifyCode.append(t);
                        i++;
                    }
                }
                break;
            case TYPE_LETTER_ONLY:
                while (i < length) {
                    int t = random.nextInt(123);
                    if ((t >= 97 || (t >= 65 && t <= 90)) && (null == excludeString || excludeString.indexOf((char) t) < 0)) {
                        verifyCode.append((char) t);
                        i++;
                    }
                }
                break;
            case TYPE_ALL_MIXED:
                while (i < length) {
                    int t = random.nextInt(123);
                    if ((t >= 97 || (t >= 65 && t <= 90) || (t >= 48 && t <= 57)) && (null == excludeString || excludeString.indexOf((char) t) < 0)) {
                        verifyCode.append((char) t);
                        i++;
                    }
                }
                break;
            case TYPE_NUM_UPPER:
                while (i < length) {
                    int t = random.nextInt(91);
                    if ((t >= 65 || (t >= 48 && t <= 57)) && (null == excludeString || excludeString.indexOf((char) t) < 0)) {
                        verifyCode.append((char) t);
                        i++;
                    }
                }
                break;
            case TYPE_NUM_LOWER:
                while (i < length) {
                    int t = random.nextInt(123);
                    if ((t >= 97 || (t >= 48 && t <= 57)) && (null == excludeString || excludeString.indexOf((char) t) < 0)) {
                        verifyCode.append((char) t);
                        i++;
                    }
                }
                break;
            case TYPE_UPPER_ONLY:
                while (i < length) {
                    int t = random.nextInt(91);
                    if ((t >= 65) && (null == excludeString || excludeString.indexOf((char) t) < 0)) {
                        verifyCode.append((char) t);
                        i++;
                    }
                }
                break;
            case TYPE_LOWER_ONLY:
                while (i < length) {
                    int t = random.nextInt(123);
                    if ((t >= 97) && (null == excludeString || excludeString.indexOf((char) t) < 0)) {
                        verifyCode.append((char) t);
                        i++;
                    }
                }
                break;
        }
        return verifyCode.toString();
    }

    /**
     * 已有验证,生成验证码图
     *
     * @param textCode       文本验证
     * @param width          图片宽度(注意此宽度若过小,容易造成验证码文本显示不4个字符的文本可使)
     * @param height         图片高度
     * @param interLine      图片中干扰线的条
     * @param randomLocation 每个字符的高低位置是否随
     * @param backColor      图片颜色,若为null则表示采用随机颜
     * @param foreColor      字体颜色,若为null则表示采用随机颜
     * @param lineColor      干扰线颜,若为null则表示采用随机颜
     * @return 图片缓存对象
     */
    public static BufferedImage generateImageCode(String textCode,
                                                  int width,
                                                  int height,
                                                  int interLine,
                                                  boolean randomLocation,
                                                  Color backColor,
                                                  Color foreColor,
                                                  Color lineColor) {
        //创建内存图像  
        BufferedImage bufferedImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
        //获取图形上下�?  
        Graphics graphics = bufferedImage.getGraphics();
        //画背景图  
        graphics.setColor(null == backColor ? generateRandomColor() : backColor);
        graphics.fillRect(0, 0, width, height);
        //画干扰线  
        Random random = new Random();
        if (interLine > 0) {
            int x = 0, y = 0, x1 = width, y1 = 0;
            for (int i = 0; i < interLine; i++) {
                graphics.setColor(null == lineColor ? generateRandomColor() : lineColor);
                y = random.nextInt(height);
                y1 = random.nextInt(height);
                graphics.drawLine(x, y, x1, y1);
            }
        }
        //字体大小为图片高度的80%  
        int fsize = (int) (height * 0.8);
        int fx = height - fsize;
        int fy = fsize;
        //设定字体  
        graphics.setFont(new Font("Default", Font.PLAIN, fsize));
        //写验证码字符  
        for (int i = 0; i < textCode.length(); i++) {
            fy = randomLocation ? (int) ((Math.random() * 0.3 + 0.6) * height) : fy;
            graphics.setColor(null == foreColor ? generateRandomColor() : foreColor);
            //将验证码字符显示到图象中  
            graphics.drawString(textCode.charAt(i) + "", fx, fy);
            fx += fsize * 0.9;
        }
        graphics.dispose();
        return bufferedImage;
    }
}
